Thursday, May 27, 2010

Design for Wildlife part 1, Design for Bees

Honey bees have been getting press coverage lately with Colony Collapse Disorder, a yet undetermined affliction that has killed more than a third of the US bee population every year for the last four years. Honey bees have co-evolved with humans for centuries, and a collapse of these pollinators would mean a reduction by 1/3 of all the food produced in the United States. This is a serious matter that is just one piece of evidence of how broken our national food production is in this country, but I'll save that for another blog entry. What's certain about this is that we will become increasingly more dependent on the pollination of native bees for our crops. Most people are familiar with honey bees and bumble bees, but many of the small flying insects who frequent flowers are also bees. In fact, 3/4 of the planet's plants need insect pollination for reproduction, an evolution that occurred long before humans domesticated honey bees.

There are over 1600 species of native bees in California, with over 80 in the San Francisco Bay Area alone. They come in all color ranges, from metallic shades of blue and gold to fuzzy red, stripey green and black. The female Valley Carpenter Bee, reminds me of an orangutan with her gorgeous orange fur. Her mate is blue and shiny.
This bee in the poppy in Halictus escholzia, a sweat bee. 
Bees have a wide size range, from smaller than your pinky nail to the length of your thumb, often in the same family. The little bee down here is the smallest of San Francisco's carpenter bees, Ceratina acanthus.

Recently I had the pleasure of catching a bee called Megachile while at a friend's garden, and it buzzed with more ferocity than a cellphone on vibrate in my fingers but did not sting me. Why not, you ask? Honey bees and bumble bees have stingers, but these bees, like many animals, rely on bluff to protect them, since they sacrifice their own life to sting. If you think bees are dangerous then you have them mixed up with their cousins the wasps and hornets, who are aggressive and sting multiple times. Bumble bees and honey bees are social and live in hives of many thousands of individuals, meaning that they have a reason to protect the rest of their sisters in their hive by stinging. As a beekeeper I can assure you that even when opening up the lid of their boxes these bees rarely sting. They've been selectively bred to be gentle.
The rest of our native bees are solitary, most not even possessing a stinger at all. The solitary bees differ from honey bees in more ways than just that. Solitary bees have a shorter season when they're actively pollinating flowers, and have often evolved to coincide their life cycle with the flowering cycle of the native plants they pollinate. Many bees are specialists and feed only on one plant or one family of plants, such as the Sunflower bee Diadasia enavata, who pollinates many plants in the sunflower family. Scientists and farmers have been experimenting with these and other specialized pollinators such as the megachile family of bees. The short season of the bees can be be extended by staggering the times bees hatch, they do this by keeping sone of the nests in shade, and bringing them out to warm in succession, and as the nests warm the baby bees hatch.
If you want to have these amazing creatures in you garden, it isn't the size of your planting bed that will entice them- as most only need 16 square foot of space to lure them in to explore.  What bees need most are plants that have evolved to time their flowering to the bees, habitat, and water.
Gordon Frankie and his Berkeley Bee Garden group have been working to give the public more information on native bee habitat.  Check out their website for hours of information, including plant lists and beautiful photos.